"SBS is usually caused by a frustrated parent or caregiver who shakes a baby when it will not stop crying, or because of some other personal stress like money or relationship problems," the New York State Department of Health says on its website. "It only takes a few seconds of violent shaking to cause permanent damage."

To help bring awareness to this issue is the Click for Babies campaign — which gets its name from the clicking sound that knitters make with their needles. During the campaign, communities across the U.S. are asked to donate handmade purple hats for babies. New parents will receive these hats, along with a video, booklet, and bedside information describing what the National Center on Shaken Baby Syndrome refers to as "PURPLE crying," which describes a period of time when infant crying increases. It typically begins when a baby is about 2 weeks old until 3 to 5 months.

"The collaboration and coordination it takes to make the caps, distribute them to hospitals, and deliver them to parents provides a fantastic opportunity to bring the whole community together in an effort to raise awareness about this important issue," according to the campaign's website. "The goal of the CLICK for Babies campaign is to increase awareness and educate others about the Period of PURPLE Crying that all infants go through, how to respond to prolonged crying, and the importance of never shaking your child — all in an effort to prevent the shaking and abuse of infants."

To help knitters, Click for Babies offers knit and crochet pattern and instructions on baby friendly yarns and the proper size. People can then either drop them off or mail their purple knitted caps to a designated drop off locations until October 1. After that, the purple hats will be distributed at hospitals.